Induced seismicity is a common phenomenon that occurs as soon as the stress state in the subsurface is externally altered in a way that faults are destabilized. It is especially problematic in stable tectonic regions where the area is not used to earthquakes; the infrastructure is not built to withstand ground movement and thus when the induced seismicity occurs damage can follow. In this thesis, mining-induced seismicity has been studied at the Dannemora mine, located in central Sweden, with the aim to locate the seismicity and gain understanding of its occurrence and behavior. The mining company, Dannemora Mineral AB, provided with blasting locations and times, as well as maps over the mine's orebodies and stopes. Seismic data acquired between 01 July 2014 - 25 March 2015 from 4 temporary seismic stations, deployed in the summer of 2014 surrounding the mine, along with 8 SNSN stations was analyzed. The project encompassed field work and processing of the data, which involved different methods to investigate the characteristics of the mine's seismicity: Statistics were kept to record the activity rate of the seismicity over time; spectral analysis was used to study the frequency content of the seismicity; particle motion plots were constructed to identify body-phases in the seismicity; Local Earthquake Tomography was used to upgrade the velocity model of the mine and to relocate the induced seismicity with more accuracy; cross-correlation was used to find events originating from similar sources; and finally, magnitude analysis was used to compare the different types of seismicity within the mine. Three main types of induced events were observed in the mine: low-frequency events with clear first arrivals, emergent events with long duration, and high-frequency events that could either have clear first arrivals or emergent-like with long durations. Through the analysis of their characteristics, they were linked to different types of rockbursts. The low-frequency events were linked to both reactivation of fault zones triggered by the mine activity, and rockbursts within the mine directly related to the mining. The emergent and high-frequency events were also linked to rockbursts directly related to the mine activity, e.g. ejection of rock from the tunnel walls or arch collapses in stopes.

By studying the frequency domain of seismic signals generated by earthquakes, the source parameters can be recovered, i.e., the seismic moment (M0) and the stress drop (Δσ). This method is an advantage especially since if the source parameters are calculated from the time domain a full waveform inversion is needed, therefore this procedure facilitates the computation. Besides, the moment magnitude (Mw) can be calculated from the seismic moment and, in turn, the local magnitude (ML) can be obtained by using an algorithm that matches different ranges of moment magnitude with their corresponding local magnitude. In the present thesis, small to moderate earthquakes in Northern Sweden have been used to develop a code that calculates the source parameters through the fitting of five different spectral models and, this way, discerns which model obtains the best determination of the parameters. These models have been chosen in a way that we can also extract information about the attenuation. The different models are; the Brune spectral model, Boatwright spectral model, Boatwright spectral model with a fixed fall-off rate, a general form of the spectral model with quality factor equal to 1000 and a general form of the spectral model with quality factor equal to 600. Among these models, the Boatwright model with fixed fall-off rate equal to 2, has been found to give the best fit to the data used in this thesis. This might be due to the regional conditions which are the low attenuation in the crust of northern Fennoscandia and the short hypocentral distances of the studied earthquakes. The earthquakes studied in the present thesis have shown a range of magnitudes from ML 4.2 to -0.2 with radius of an assumed circular fault ranging from 269 m to 66 m.